The invention relates to a gas bag module for a vehicle occupant restraint system.
In German Utility Model 297 21 682 is shown a gas bag module for a vehicle occupant restraint system, comprising a gas bag, a gas generator being in flow connection with the gas bag, and at least one cover part covering the gas bag against a passenger compartment when the gas bag module is mounted in a vehicle. The cover part is pivoted about a hinge portion after activation of the gas generator in order to enable the aid gas bag to exit into the passenger compartment. There is provided at least one traction transfer means having a first and a second end. The first end is attached to the cover part, and the traction transfer means exerts a tensile force on the cover part when the gas generator is activated. This construction reduces the risk of a vehicle occupant being injured by a cover which is opening. One drawback of this solution resides in that the cover members are guided in an expensive manner. Moreover, a great tensioning is required in the traction transfer means, due to the force reversal effected by the guide and the friction associated therewith, for the cover to burst at the predetermined breaking-point provided therefor.
The aim of the invention is to provide a gas bag module in which the cover may be opened in a simple manner without any risk existing for the vehicle occupants in case of activation.
The invention provides a gas bag module for a vehicle occupant restraint system, comprising a gas bag, a gas generator being in flow connection with the gas bag, and at least one cover part adapted to cover the gas bag against a passenger compartment when the gas bag module is mounted in a vehicle. The cover part has a hinge portion which allows the cover part to pivot from a closed condition into an opened condition in which the gas bag is able to exit from the gas bag module, and further having an edge opposite the hinge portion. At least one traction transfer means is provided which has a first and a second end and is adapted to exert a tensile force on the cover part after activation of the gas generator. The first end of the traction transfer means is attached to the edge of the cover part so that the cover part opens in a direction towards the gas bag due to the tensile force exerted by the traction transfer means. Due to this configuration, the cover part executes a very simple movement, namely some turning-in towards the gas bag. Thus, no guide is required for the cover part, which is why no frictional forces occur.
According to one embodiment of the invention, two cover parts are provided which are configured integrally with the instrument panel so that the gas bag may be accommodated to be invisible from the passenger compartment. In this case, there is provided an advantageous path of forces when the instrument panel is ripped up, since the opening force is introduced centrally.
A further embodiment of the invention provides a housing which surrounds the gas bag and the gas generator and is movable against the ejection direction of the gas bag in the case of triggering the gas generator, the traction transfer means being attached to the housing so that the opening force is introduced, by the housing movement, onto the cover parts via the traction transfer means and that the traction transfer means and the opened cover means constituting an ejection path for the gas bag in the activated condition of the gas generator. Thus, the gas bag may freely and rapidly unfold without any risk that it is damaged or gets stuck and suddenly unfolds when it is released again.
Further details and configurations of the invention read from the subclaims.